抽油机井油管接头弹塑性接触有限元分析

对油管接头进行弹塑性接触有限元分析，给出其应力分布规律，找出应力集中区即螺纹尾部第一啮合齿根；讨论各种载荷及锥度偏差对应力分布的影响，得出拉伸载荷对油管应力应变场的影响很大；油管极大锥度、接箍极小锥度使油管接头螺纹尾部第一啮合齿根应力集中区进一步扩大，而油管极小锥度、接箍极大锥度则会造成油管在端部附近断裂或粘扣，这两种情况都比较危险，因此在使用中应尽量限制锥度偏差。同时也对公称锥度的油管接头进行在循环载荷作用下的有限元分析，确定油管的疲劳失效类型属于高周疲劳。

FINITE ELEMENT ANALYSIS OF ELASTOPLASTICITY CONTACT OF TUBULAR JOINTS

The work of analyzing tubular joints by means of finite element method in the range of linear elasticity and plasticity was done. The distributions of stresses and strains were given. It is found that stresses and strains are always concentrated in the root of the first joggle round and certain yielding comes up in this area. The effects of all kinds of loads and the taper deviation of the tubular joints upon the distributions of stresses are also discussed. The distributions of stresses and strains of tubular joints are influenced seriously by the load of tension, and the concentrative section in the root of the first joggle round will be extended in the case of maximum taper pin and minimum taper box. The fracture will arise at the end of tubular joints in the case of minimum taper pin and maximum taper box, both of the cases are dangerous, so the taper deviation of the tubular joints should be limited strictly in use. At the same time, the mechanical characteristics what the nominal taper tubular joints subjected to the cycle tension load exhibit are discussed, and the failure tape of the fatigue belongs to high cycle fatigue.